RADAR-6702 | Add slack cloud data source onboarding doc (#1413)

Please go to the `Preview` tab and select the appropriate template:

*
[Consul](?expand=1&labels=Consul&title=Consul+Docs&template=consul_pull_request_template.md)
* [HCP services](?expand=1&template=hcp_pull_request_template.md)
*
[Nomad](?expand=1&labels=Nomad&title=Nomad+Docs&template=nomad_pull_request_template.md)
* [Terraform
Enterprise](?expand=1&template=ptfe_release_pull_request_template.md)

Author: jonathanfrappier

content/hcp-docs/content/docs/vault-radar/get-started/add-data-sources/slack.mdx

@@ -0,0 +1,61 @@
+---
+page_title: Add a data source - Slack
+description: >-
+  Add Slack as a data source for Vault Radar.
+---
+
+# Onboard a Slack data source
+
+@include 'private-beta-feature.mdx'
+
+HCP Vault Radar allows you to connect to any workspace on [Slack
+](#onboard-slack) and scan for secrets in public channels.
+
+## Prerequisites
+
+- Permission in Slack to install third-party apps from the marketplace.
+
+   <Highlight title="Known limitations">
+
+   Vault Radar has a limit of 5000 channels per workspace. If you have more
+   than 5000 channels, Vault Radar selects the 5000 channels with the
+   most recent activity.
+
+   </Highlight>
+
+## Add a Slack Data source
+
+1. Click **Settings/Data Sources**.
+
+1. Select **HCP Vault Radar Scan**.
+
+1. Under **Team Collaboration**, click **Slack**.
+   ![Select Slack data source](/img/docs/vault-radar/slack-onboarding-flow.png)
+
+1. Click **Connect to Slack** to **install the Slack app**. This initiates
+   the OAuth flow with Slack.
+
+1. Select the **Slack workspace** from the dropdown list and click **Allow**
+   ![Install Slack App onto a workspace](/img/docs/vault-radar/install-slack-app-to-workspace.png)
+
+   <Note title="Permission required to install Slack app">
+
+   If you do not have permission to install apps into the selected workspace,
+   you will see a **Submit Request** button instead of the **Allow** button.
+
+   Coordinate with your Slack workspace administrator to approve the app
+   installation.
+
+   </Note>
+
+   HCP Vault Radar displays the message **Authenticated to Slack**.
+
+1. Click **Next**.
+
+1. Select either **All active channels** or **Select channels to monitor**.
+
+   The onboarding workflow joins the Slack app to the selected channels. If you
+   have a large number of channels, this process will take several minutes to
+   complete.
+
+1. Click **Finish** to start onboarding and scanning the selected channels.

content/hcp-docs/content/partials/private-beta-feature.mdx

@@ -0,0 +1,7 @@
+<Note title="Private beta feature">
+
+This feature is available as an _invitation only beta release_. Beta functionality is stable
+but possibly incomplete and subject to change. We strongly discourage using beta
+features in production.
+
+</Note>

content/hcp-docs/data/docs-nav-data.json

@@ -702,6 +702,10 @@
                     "path": "vault-radar/get-started/add-data-sources/jira/jira-data-center"
                   }
                 ]
+              },
+              {
+                "title": "Slack <sup>Beta</sup>",
+                "path": "vault-radar/get-started/add-data-sources/slack/"
               }
             ]
           },